It is known to clear drain lines and the like of accumulated obstructions by the use of high-pressure water carried by a hose inserted into the line. Such prior uses utilize jets aimed rearwardly to aid in advancing the hose through the line. Prior apparatuses are characterized by low efficiency and relatively high costs. Attempts to improve jet-powered machines include water-motor cutters for cases where the drain line may be clogged by roots, for example, but such water-motors are even more costly and difficult to operate.
According the present invention, an improved thruster is provided, eliminating the need for mechanical or water vane motor driving means and instead relying on properly placed jet means not only to assist in advance of the thruster but to create a rotary action particularly effective for cutting roots and the like in the drain line. The invention in one form features a thruster having a body of at least hemi-spherical configuration about a fore-and-aft axis, the front part of the body providing an annular frontal area of rearwardly and radially outwardly sloped disposition. A coaxial forward extension of the body is provided with a jet means aimed to direct high-pressure water closely over the frontal area to combine a thrusting action with the effects of vacuum or low-pressure to augment the advance of the thruster through a drain line or comparable environment. In one form of the invention, the forward extension is cylindrical and journals a spinner head which is rotated by additional jet means configured to act on the spinner head in such a manner as to drive the spinner head. The spinner head may also carry blade or whip-like elements to facilitate the use of the thruster in extreme situations, as where the drain line has been penetrated by tree roots.
A further feature of the invention is that the thruster body is carried by means providing for selective fore-and-aft positioning thereof relative to the jets so as to vary the relationship between the frontal area of the body and the jets. Still further, provision is made for adjusting the sizes of the rearwardly directed jet means. Yet another feature is the provision of cooperative frusto-conical portions of the thrusters to form fan jet means, and further to make axial adjustment of those portions to vary the size of the fan jet means.
The foregoing and other features and advantages of the invention will become apparent as the invention is disclosed in the ensuing description and accompanying drawings.